Tuned receiver tube



Aug. 30, 1932. s. LOEWE TUNED RECEIvER TUBE Filed 0G15. 25. 1926 Fay 3 INVENTOR SlEMUND LOEWE TORNEY -F 'the anode.

" purposes, part ofthe Patented Aug. 30, 1932 y' UNITED STATES PATENT ortica lSIEGfllznlrrn) LOEWE, 0E BEELIN-rR1ED'ENAU, GERMANY, AssIGNoE 'ro RADIO oonrona- 'rIoN or AMERICA, e.'combatirlo.1vy 0E k:oELAvs/'AEE TUNED RECEIVER 'TUBE 'Application med october 25, 1926, serial No.

l A.It hasl recently been suggested in-.the radio artto enclose in receiver` tubes a part of the other circuit elements such as coils, highohmic resistances, and4 coupling condenser.

owever, one essential feature of the problem to be solved in this connection remained unsolved in s o far as n0 Ways and means have been known to mount tuned elements inthe tube in such a manner that the tube would handle only a very definite frequency, while remaining inoperative or opaque in the case of other frequencies. y

It is an object of this invention to provide a vacuum tube whichis highly selective..

lIt is a further object of this invention to provide a space current device which will be responsive only to a definite frequency.

The manner of carrying out this invention ywill be readily apparent from the following description taken in connection with the accompanying drawing in which Y .Figure 1 is a diagrammatic view of a device embodying-the invention.

iOures 2, 3, 4, and 5-are modifications of device shown in Figure 1.

Y In Figure 1 is shown a vacuum tube comprising a hot cathode 1,.grid 2. and'platey or anode 9. Inside this vacuum tube, to be more precise, between the cathode and the grid,or as shown in Figure 3 between grid andplate, there is mounted a means adapted to produce or allow of the selection of a definite frequency. The said means of Figure l consists of a piece of quartz crystal 3 or other piezo-electric material which is carried by a support 4 preferablymade of metal and connected with the cathode.' `In Fig. 4 theV crystal support is shown connected to the The piezo-electric excitation of the saidquartz crystal is effected by the alternatirng current potentials that are fed in or which are generated inside the tube, said potentials being of a frequency to which the said quartz crystal is tuned.4 For excitation gridcircuit is formed plate-fashion as indicated at 5, so that the quartz crystal comes to be located inside an electrical field. Now, if between the terminals 6 and 7, alternating current potentials A are supplied, the grid 2 becomes subject to 143,889, and in Germany November 4, 1925.

a marked supplementary excitation provided the incoming wave is exactly equal to the natural period or to a harmonic of the quartz crystal. The arrangement may be modified in a way as indicated in Figure 2. The grid lead 6 is brought inside the tube to a freeended electrode which is mounted opposite the quartz crystal 3.` The grid itself is united with a point on the surface of the said quartz crystal, for instance, by a wire 8 brought close `to saidy surface. In the presence of resonance of the quartz crystal, it receives strong charges whereby the flow of electrons across the tube to the plate 9 is controlled. [n this manner, very strong periodic altermating current potentials having the period of the quartz crystal are obtained at the consuming or working device 10, which may be connected, for example, between plate and cathode by way of battery 11. vThe action effect, so that the grid which is renderedV markedly positive by virtue of the piezoelectric potentials, receives charges from the filament which gradually make the grid potentials negative whereby a strongy alteration of the plate current is occasioned. Parts 12 and 13 may be built directly into the tube.

InV Figure 3 another embodiment of the idea underlying the invention is illustrated, In this case, the grid is built in the usual manner, but the plate 9 bears a quartz crystal 14 in such a way that the same is of free oscillations, with its piezo-electric potentials becoming thus added to the plate potentials. The plate or anode embraces or envelops the surface of the quartz crystal turned towards the ilament in the form of spangleor buckle-shaped pieces l5. Now, if the incoming wave is equal to the frequency of resonance of the quartz crystal, the piezoelectric potential becomes added to the poten tial of the plate. In the presence of resonance, and if the plate potential is set to a convenient constant value, there occurs a capable sol inrconformity with well known rulesrfor thermionic tubes arrangements can be so made that the positive piezo-electric potentials yresult in a substantial increase in the plate current, Whereas ther negative potentials occasion no decreaseof the same. In` the presence of other'adjustments, the meanval# ue of the plate current undergoesnoalterations, but then a substantiallyamplifiedv al-v ternating current component; .arises the', plate current; but this happenso'nly' if the exciting frequency isr equal to the periodi` of further developmentV ofv the' schemel as` illusoscillation of the quartz crystal or one of'v its overtones. Y y Of particular value and importance is the trated in -Figure'll which ris amultipleLunit systembuilt intofone tube ywhich is niade highlysele'ctive for deiinite 'frequenciesicor--, 1 responding quartzcrystal possessing piezo-electric prop-V ltothe particular period of the erties andy which is mounted inside the said tube. 'f'lVhile in the case offFi'gure l another dispositionisaevidentlthat also one Vof the'scheines illus'- trated-inFigures l to 3 maybe used with the sanieend in View.v L f l/Vithiii alsingle vacuum vessel 16 isyrsealed the' said- I'multiple-unit system comprising cathodes 17', 18, (preferably connected-*inseries) ,l thegrids 19,v 20,

lsystems: iis vused 'the'lpiezo-electri'c quartz Y be" excited, for -in" stance,'bythe electrodes26. The lead-insor-V sealsv are'` denoted by 27, 28, 29and' '30, andcrystal y which may these are brought tot'heffirst grid-,the heatinglfil'anientsmn'd the' iirst y'and second plates, respectively.- yThe platev lead l`of theiirst plate may contain'the high-ohmicv resistance f 31, and also this resistance' maybe confined within fthe tube.'y

But in its stead, falsoan impedance,1e. g., a chokecoilfor thehighohmic direct current resistance 31 can be pro-* pled multiple-unit systems, thereis here ob# tained an extremely sharpsele'ctancey bythe tube yitself. Y

selectively acting therinionic'tubes ofthe type hereinbefore disclosed have a 4very wide practical application not only in radio telegraphy arts, l,butalso yini-other electrotechnica'l @5' sans.y

claim:

Y2. A ,Vacuum tube havingv iilainent, and plate elements lmounted, therein apiezo; kelectric device mounted within said ltube," vsaid piezoielectricdevice "having a natural 'period .ofgmechanical vibration, and leads of the quartz crystal isshownfit` the plates or anodes21-,1 22, the stopper condenser 23,*an'd the leak reef sistance 24. As coupling means between both i tuned Vto the periods fof oscilla-` These potentialsv coupler con-V denser 23, and control/action bythe grid 2O,l wherebycorresponding control of lthe plate' current in the second; system is'occasioned. n Contradistinct from l known "resistai'ice-'cou-r VHaving thus described my invention, '1i

- 1. A vacuum tube having three electrodes and a piezo-electric control element mounted i therein, said element being coupled to two of said electrodesy and :beingjaresporisive to only a .predetermined'- frequency.-

connecting said device to said grid-and one` of said other; elements, said piezo-'electric device cocperating with the said elements and the saidsilea'ds -t`o forinanlalternatingcurrent circuit iwhose periodf'is" governed "f-by'fsai'd f device.

A `yvacuum tube 1 Vand?plateelements mounted therein, a-'pie'z'ol lelectric. device," mounted within said tube, said pi'ezoz-electr-icE devicehaving 1a natural periodof mechanical: vibration and coupled directly? grid y tosaid grid and one of said'.otherleleinents,ll

saidv piezoe'electric v'devicek forminglwitli said electrode'slt'o which 'it is f connectedan alterLA frequency atwhi'ch saidtube operates K' i 1. .sA r`vacuum tube having lila-ment,l grid and platev yelectrodes-'fand 'i afffreqnency de; '0. i'

x nating current circuit whichdetermines theV v terininiiig ineans, "completely mounted. r

within said! tube, 'saidf meansVT comprising'av piezo-electric bodyhaving ai' natural'gvperiod said :bodytotwoofjsaidelectrodes.' p 5. vacuumtube fhaving--iilai neiit, and plate'lelements', .and frequency Adeter,-

mining means, all-conipletely 'mounted with'-`V ofm'eclianical?vibration,- aiid 'meansAK coupling' in'said tube, vsaid means comprisingipiezof electric body liavinggfa natural period of mechanical vibration,A and -ineans'ccnnecting saidbody to said grid said4 iilainent's A vacuum `tubev havingfiilaineiit,'gridA` i and plate felenients, and a f frequency deter-v miningmeans, all` Completelyfineun'ted' withiny said 1tube,jsaidmeans comprising 'ajpie'zo-V electricfbody havinga naturalf'periodf of melf kch'ani cal vibration, l and means-coupling saidA body t0 Said pl'ate'and sadfiiamenfw-- Y 7 Aniulti-stage vacuum tube eachjstage of which has a iilair'ienilg,r grid. and :plate .elmy trede, all of `-whi'ch"'electrodes areincluded` within said tube, inl combiiiatioiil with ir'ieans` electric i means coupled to electrodes`v withinv saidtfube, serving asia frequency determining element'jfor 'saidstages, both `said last inen-` v` f ti'onedjjineans being included Within*said-L eibe'.- i 

